The submarine, names the "INS Tannin," is also said to be equipped with special diesel and hydrogen conversion systems that will allow it to produce its own fuel; as well as with a stealth system making its acoustic signature virtually undetectable by sonar.

The INS Tannin ("Alligator") is the namesake of the Israel Navy's first ever S-Class submarine, which was retired from active duty in 1972.

According to German media, the Tannin – which will be supplied by the end of 2012 – is the first of three super-submarine slated to eventually be deployed by the Navy. A second super-sub – the INS Rahav ("Splendor") will arrive in 2014 and the third, which has yet to be named, by 2015.

Germany's Kieler Nachrichten newspaper said that the super-sub is the biggest and most advanced underwater vessel to be constructed in Germany since World War II.

It has also been acquired by the German and Italian naval forces.

The boatyard where the submarine is under construction is said to be under heavy guard. A team of Israeli experts is on-site, assisting their German counterparts.